This invention relates to a tool for mounting to a press and mass inserting a plurality of contact pins depending from a connector into a printed circuit board, and particularly to a tool for use in concert with like tools on a hydraulic press having a magnetic chuck.
U.S. Pat. No. 4,383,361 discloses a connector insertion tool for mounting to a press and mass inserting a plurality of contact pins depending from a connector into a printed circuit board, the tool being of the type comprising a body having a top surface and an opposed bottom surface, two rows of insertion fingers extending from the bottom surface, and guide means slidably mounted on the fingers. Shaft means fixed to said guide means is slidably received in bore means in the body, and spring means is effective to urge the guide means away from the body when the body is mounted to the press. The guide means is received in the card-receiving slot of a card edge connector and serves to align it for reception of the insertion fingers during the downstroke of a press to which the tool is mounted. As the downstroke progresses, the insertion fingers move into apertures in the connector housing and the guide means moves toward the body. The shaft means, in the form of a solid rod, emerges from the top surface as the spring means, in the form of a coil concentric to the rod, is compressed. The bottom surface or chuck of the press must thus be profiled with an array of holes to receive the rods emerging from the top surface of the tool body. Since the tools are generally used in concert with like tools to apply a group of connectors to a printed circuit board, the array of holes in the chuck must match the printed circuit board. Thus the chuck would have to be changed for different PCB's.
One solution to the problem of the emerging shaft means is to design a tool with a body high enough to contain the shaft therein as the guide moves toward the bottom surface of the tool body. However, some means for fixing the tool to the chuck is still required. A magnetic chuck which holds the tool thereto by electromagnetism would thus permit a chuck surface to which any array of tools with steel top surfaces could be fixed.
U.S. application Ser. No. 618,983, a companion application filed concurrently with this application, and hereby incorporated by reference, describes a method suitable for mass mounting connectors to a PCB, using a hydraulic press having a magnetic chuck, as well as necessary apparatus. The method of force-fitting components into a PCB comprises the steps of: locating in alignment with a magnetic chuck on a press platen, a dummy workpiece having tool supports fixed thereto in a predetermined array with predetermined spacing therebetween and a component insertion tool removably surmounting each tool support; moving the platen towards the workpiece to secure each tool magnetically to the chuck; withdrawing the platen thereby to remove each tool from the support surmounted thereby; replacing the dummy workpiece by an actual workpiece with components arranged thereon in said predetermined array and with said predetermined spacing therebetween; and moving the platen with the tools thereon towards the dummy workpiece to cause each tool on the chuck to force-fit the corresponding component into the actual workpiece.
A new dummy workpiece can be prepared each time the arrangement of, or the nature of, the components on the workpiece is to be modified. The labor and expense of mounting fresh permanent tooling to the platen is thereby avoided.
The described method involves mounting the insertion tool to a tool support on a dummy workpiece, which in practice may be a card edge connector mounted to a printed circuit board. The magnetic chuck then picks up the tool. A problem arises with a tool of the type having a high body containing the rod therein insofar as the height of such a tool causes any angular displacement or leaning of the tool to increase the misalignment of the tool when it is withdrawn from the dummy workpiece. Any leaning is aggravated by the high center of gravity associated with such a tool.